One of today's most popular recreational and professional sports is tennis. Interest in tennis is not limited to the U.S. but extends very nearly to the entire world. The sport of tennis has its origins hundreds of years ago and most sports fans have heard of the Wimbledon tournament which is nearly as old as the sport itself.
Naturally, the rules and regulations of the sport have been clearly defined. For instance, a tennis ball intended for professional use must be inflated to precise specifications during manufacture. However, once shipped from the factory, some tennis balls may lose some of their resiliency and become defective. Once in the hands of the user the only way to test for these deficiencies is by a rudimentary test of bouncing the ball on the playing surface or by squeezing it, neither of which is very accurate. The present invention is concerned with this problem. More particularly, the present invention is concerned with a manner in which a player can quickly and efficiently determine whether or not a ball is suitable for play.
As might be expected, there is no shortage of devices for testing the compressibility of a ball. For example, U.S. Pat. No. 3,665,757, issued to Hoag, discloses a device for checking the concentricity and compression of a golf ball. Hoag utilizes a lever for exerting a force upon the golf ball, forcing the golf ball against a spring gauge to measure the compressibility of the golf ball. See also U.S. Pat. No. 2,278,416, issued to Atti, which discloses a similar device.
U.S. Pat. No. 2,628,496, issued to Wick, discloses a portable golf ball tester. This device is similar to those disclosed in the above-mentioned references except for the manner in which force is exerted upon the ball. In Wick, the force is exerted upon the surface of the golf ball by a screw which when tightened increases the force exerted upon the ball being tested.
However, none of the above patents discloses a portable device which provides the user with a quick and efficient means to determine whether a ball is suitable for play. U.S. Pat. No. 5,222,391 issued to Reenstra discloses a device which attempts to address these deficiencies. Reenstra discloses a device which compresses a tennis ball to a predetermined size. This predetermined size is the maximum allowable for a tennis ball that is suitable for play when placed under an eighteen pound load. This device incorporates an electronic sensor that determines whether eighteen pounds of pressure was used to deform the ball.
However, Reenstra does not indicate how much pressure is actually being used, the device only indicates if eighteen pounds of pressure was used to deform the ball. Also, the device housing in Reenstra is strictly designed to test tennis-sized balls only, there is no allowance for adaptability to test other types of balls. In addition, Reenstra relies on an electronic sensor that is subject to failure and may be susceptible to environmental conditions encountered on the court.